feat(example): stream peer-hosted audio and images over httpi://

[momics]

Summary

Showcase a cross-runtime flow where the Deno example hosts a directory of files and the Tauri example streams them straight into native media elements through the httpi:// scheme handler — no IPC bridging, no base64.

Deno (host)

• Add a host task that wires @std/http's serveDir over node.serve to host ./public over httpi:// — a vanilla file server, no custom HTTP code (per ADR-013, lean on the ecosystem).
• Ship procedurally generated, public-domain audio.wav (WAVE PCM 16-bit mono 44.1 kHz) and image.png (256×256 RGBA).
• Grant --allow-sys=inspector on all tasks (the FFI init requires it).

Tauri (client)

• Enable the httpi:// scheme via builder().with_scheme().
• Replace the Audio tab with a Stream files tab that loads peer-hosted audio (<audio>, with Range seeking) and images (<img>) by host node ID.
• Widen the CSP to allow httpi: / http://httpi.localhost media and images.

Notes

• The previous self-served WAV demo is removed: iroh blocks self-dialing (Connecting to ourself is not supported), tracked in Support self-requests (a node fetching its own node ID) via in-process loopback #264.

Testing

• Verified end-to-end locally: deno task host serves /audio.wav + /image.png; the Tauri Stream files tab plays the audio and renders the image after pasting the host's node ID.
• cargo check passes for the example; npm run tauri dev launches; deno check main.ts clean; example main.ts has no TS errors.